Coombs test

(Koomz)

[R.R.A. Coombs, Brit. immunologist, 1921-2006]
A laboratory test for the presence of antibodies, usually blood type antibodies, in serum. The patient's serum is incubated with red blood cells (RBCs) with known antigenic markers; if antibodies to the antigen are present in the serum, they bind with the RBCs. When antihuman globulin is added, RBC clumping (agglutination) occurs. The test is used for crossmatching blood before transfusions to ensure that no antigen-antibody reactions will occur and to test for the presence of specific antibodies to RBCs.